This document discusses the history and components of virtual reality systems. It begins by defining virtual reality as an artificial 3D environment created by computer hardware and software that users can interact with and appears real. The document then summarizes the history of virtual reality from its origins in the 1980s to current applications. It describes the key components of virtual reality systems including head mounted displays, audio units, gloves, and reality engines. It also discusses types of virtual reality systems from non-immersive to fully immersive and how immersion is experienced by users. The document concludes by outlining advantages and disadvantages of virtual reality systems.

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VIRTUAL REALITY SYSTEM
Research Paper—Information Technology *Anusha. G
1. WHAT DOES VIRTUAL REALITY MEAN? commercial system for controlling computer simulations
Virtual reality (VR) is an artificial environment through a dataglove and a stereoscopic Head-mounted
created with computer hardware and software and Display (HMD). An artist himself, Lanier introduced
presented to the user in such a way that it appears like Virtual Reality as a medium for shared self-expression.
a real environment. It is a synthetic technology Over the past decades, two major streams of VR
combining three-dimensional video, audio, and other emerged: the one stream based on the HMD and the
sensory components to achieve a sense of immersion other stream based on the room-size projection of
in an interactive, computer-generated environment. To graphics for unencumbered interaction.
enter a virtual reality, a user dons special gloves, The helmet-based stream of VR emerged from
earphones, and goggles, all of which receive their input military flight simulators. Frederick P. Brooks founded
from the computer system,and in this way, at least three the virtual worlds laboratory at the University of North
of the five senses are controlled by the computer. Carolina. Brooks began designing virtual worlds for
2. VIRTUAL REALITY HISTORY solving problems in medicine, physics, and
The term virtual reality first appeared in the late engineering. The other stream of Virtual Reality (VR)
1980s in Jaron Lanier’s Virtual Programming Languages development came from the art world. Another
Incorporated (VPL), which introduced the first environment, Psychic Space, allows participants to
VIRTUAL REALITY 3D MOUSE
explore an interactive maze where each of footsteps ontological confidence to declare something to be real.
corresponds to a musical tone, all produced with live 3. COMPONENTS OF VIRTUAL REALITY
video images that can be moved, scaled, rotated, SYSTEMS
without regard to the usual laws of cause and effect. In its most basic form, virtual reality systems
Virtual Reality telepresence allows NASA operators in consist of a computer and software—known as the
Houston to move a Moon Rover across the lunar reality engine—and input and output sensors. A sensor
landscape while feeling as if they were actually present is a device that responds to some physical stimulus. A
in the vehicle on the Moon. Research in VR continues human eye, for example, is a sensor that responds to
to explore the issues of what gives humans the light rays. Virtual reality input/output devices include
* B.Tech (III), Jyothishmati College of Technology and Science, Karim Nagar (AP)

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head- and ear mounted equipment for hearing and AUDIO UNITS: The audio portion of virtual reality
seeing and gloves for controlling the virtual world. is transmitted through small speakers placed over each
The fourth component is the user, who directs the ear. Audio cues may include voices, singing, thud like
chosen environment and reacts to it. noises of colliding objects—in short, any sound that
REALITY ENGINE : Reality engines are based can be recorded. Sounds that seem to come from
largely on the same components that make up a above, below, or either side provide audio cues that
personal computer (PC), mimic how sounds are heard in the real world. Three-
although much more dimensional (or omnidirectional) sound further
computing power is required enhances the virtual reality experience.
for the reality engine than is GLOVES: Gloves in virtual reality allow the user
available in a standard PC. to interact with the virtual
Virtual reality images are made world. For example, the user
with tiny dot like segments of may pick up a virtual block,
a picture known as pixels, or turn it over in a virtual hand,
picture elements. Each pixel and set it on a virtual table.
itself is made up of hundreds Wired with thin fiberoptic
A HEAD-MOUNTED of thousands of dots. Realistic cables, some gloves use
DISPLAY images can be either opaque, light-emitting diodes
in which all the viewer sees is the virtual world, or see- (LEDs) to detect the
through, in which the virtual image is projected or amount of light passing
superimposed onto the outer world. To incorporate through the cable in
the total experience, the reality engine also may use relation to the movement of
haptic enhancement. Haptic experiences are those that the hand or joint. The
involve the participant’s senses of touch and pressure. computer then analyzes the
Haptic cues, however, are complex and expensive and corresponding information
have been used primarily for military and research and projects this moving
applications. Input devices are also important in VR hand into the virtual reality.
systems. . Magnetic tracking systems
HEAD MOUNTED DISPLAY (HMD): Head- also are used to determine where the hand is in space
mounted display (HMD) units use a small screen or in relation to the virtual scene. Some gloves use haptic
screens (one for each eye) that are worn in a helmet or enhancement to provide a sense of touch and
a pair glasses. Unlike a movie, where the director feel.Virtual reality gloves may use either air pressure
controls what the viewer sees, the HMD allows viewers (such as strategically placed inflated air pockets in the
to look at an image from various angles or change their glove) or vibrating transducers placed next to the skin
field of view by simply moving their heads. HMD units (such as a voice coil from a stereo speaker or alloys
usually employ cathode-ray tube (CRT) or liquid crystal that change shape through the conduction of electrical
display (LCD) technology. CRTs incorporate optic currents) to simulate tactile experience.
systems that reflect an image onto the viewer’s eye.
Although more bulky and heavy than LCD displays,
CRT systems create images that have extremely high
resolutions, making a scene seem that much more
realistic.
A DATA SUIT TO PROVIDE USER INPUT
Major HMD applications include military,
governmental (fire, police, etc.) and civilian/commercial
THE NINTENDO POWER GLOVE USED IN
(medicine, video gaming, sports, etc.).
VIRTUAL REALITY GAMING

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4. TYPES OF VIRTUAL REALITY SYSTEMS Fully Immersive Head-Mounted Display Systems:
Although it is difficult to categorise all VR systems, All fully immersive systems will give a sense of
most configurations fall into three main categories and presence that cannot be equaled by the other
each category can be ranked by the sense of immersion, approaches discussed earlier, but the sense of
or degree of presence it provides. immersion depends on several parameters including
Non-Immersive (Desktop) Systems: Non- the field of view of the HMD, the resolution, the update
immersive systems, as the name suggests, are the least rate, and contrast and illumination of the display.
immersive implementation of VR techniques. Using the 5. VIRTUAL REALITY IMMERSION
desktop system, the virtual environment(VE) is viewed Immersion is the state of consciousness where
through a portal or window by utilising a standard an immersant’s awareness of physical self is diminished
high resolution monitor. or lost by being surrounded in an engrossing total
Semi-Immersive Projection Systems: Semi- environment; often artificial. The term is also cited as a
immersive systems are a relatively new implementation frequently-used buzzword, in which case its meaning
of VR technology and borrow considerably from is intentionally vague, but carries the connotation of
technologies developed in the flight simulation field. being particularly engrossing.
A semi-immersive system will comprise a relatively high
performance graphics computing system which can
be coupled with either a large screen projector system
, multiple television projection systems .
.
CLASSIC VIRTUAL REALITY HMD
A SEMI-IMMERSIVE WIDE-SCREEN According to Ernest Adams, immersion can be
PROJECTION SYSTEM IN USE WITH SHUTTER separated into three main categories:
GLASSES Tactical immersion: Tactical immersion is
experienced when performing tactile operations that
involve skill. Players feel “in the zone” while perfecting
actions that result in success.
Strategic immersion: Strategic immersion is more
cerebral, and is associated with mental challenge.
Chess players experience strategic immersion when
choosing a correct solution among a broad array of
possibilities.
Narrative immersion: Narrative immersion occurs
when players become invested in a story, and is similar
The major components of an HMD. This to what is experienced while reading a book or watching
illustration shows the two screens capable of a movie. Staffan Björk and Jussi Holopainen, in
producing stereo images and speakers located to Patterns In Game Design, divide immersion into similar
provide stereo sound. categories.They call them sensory-motoric immersion,

4. Shodh, Samiksha aur Mulyankan (International Research Journal)—ISSN-0974-2832,Vol. II, Issue-11-12 (Dec.2009—Jan.2010) 7
cognitive immersion and emotional immersion, 6. ADV ANTAGES OF VIRTUAL REALITY SYSTEMS
respectively. In addition to these, they add three new Virtual reality has also been used extensively to
categories: treat phobias (such as a fear of heights, flying and
Spatial immersion : Spatial immersion occurs spiders) and post-traumatic stress disorder. This type
when a player feels the simulated world is perceptually of therapy has been shown to be effective in the
convincing. The player feels that he or she is really academic setting, and several commercial entities now
“there” and that a simulated world looks and feels offer it to patients.
“real”. Psychological immersion : Psychological 7. DISADVANTAGES OF VIRTUAL REALITY
immersion occurs when a player confuses the game SYSTEMS
with real life. For use of digital and computer visualization
Sensory immersion : The player experiences a techniques: Do not convey the true three-dimensional
unity of time and space as the player fuses with the nature of objects; do not convey the non-visual and
image medium, which affects impression and aural feelings of touch, smell, etc.; less beneficial than
awareness. really being in the field; lack the serendipitous nature
of discovery.
Multiple styles of access e.g. CDROM and
websites: CD-ROMs can only provide a finite limited
amount of information; visiting a website can be
difficult and depends on many factors, such as
availability of computers, load on the network, number
of connections, reliability of service provision, etc.
For Designed to be interactive like computer
games: It is easy for students to wallow, or obsess
over particular sites, which raises the problem of time
management.
8. CONCLUSION
THECA VE Finally, it can be concluded that the Virtual Reality
New technologies are currently under System makes man get immersed in a world of entities
development which claim to bring realistic that gives the feeling of reality when in fact they are
environmental effects to the players’ environment - not actually present. Virtual Reality is often used to
effects like wind, seat vibration and ambient describe a wide variety of applications, commonly
lighting.Examples: There is a motion simulators of the associated with its immersive, highly visual, 3D
Virunga Mountains in Rwanda to meet a tribe of environments. The development of CAD software,
Mountain Gorillas or a ride that takes a journey through graphics hardware acceleration, head mounted
the arteries and heart to witness the build up of plaque displays; database gloves and miniaturization have
and thus learn about cholesterol and health. helped popularize the notion.
R E F E R E N C E
* www.webopedia.com/TERM/V/virtual_reality.html * www.webopedia.com/TERM/V/virtual_reality.html*
www.agocg.ac.uk/reports/virtual/37* www. scienceclarified.com/Ti-Vi/Virtual-Reality.html* www.artificialeyes.tv/reblog*
www.articlesbase.com/.../virtual-reality